When electrical connectors are mated it is desirable to have electrical conductivity between the shells of the mated connectors. Electronic "boxes" for aircraft are often grounded to the structure of the plane. This is usually accomplished by grounding the "box" to the shell of a connector which is then mated to another connector having its shell grounded to the airplane. This provides an electrical path between the "box" and the plane.
Present attempts to provide for shell to shell conductivity include attaching a garter spring around the outside of a rectangular female connector or extending wiper blades from the shell of a circular connector. Use of these designs require high insertion forces to mate the connectors. Additionally, the wiper blades or springs fail after a few mating cycles resulting in low reliability and increased maintenance. It is therefore desirable to have a simple low cost device that will produce high repeatability and can be retrofitted to existing connectors. The device should be capable of providing continuous conductivity without interruptions due to shock or vibration.
To prevent the mating of electrically incompatible connectors, a polarizing feature is incorporated into the connectors. The ARINC 404 and 600 connectors use a male connector with a tongued post having a hexagonal head, that mates with a semi-circular aperture in the female connector. The post is capable of rotation into six different positions so that the male connector will only mate with a female connector having an aperture with the same orientation as the post.